Overriding BIOS poweroff when ACPI is disabled

[Daniel Levine <dlev89%gmail.com@localhost>]

This is probably a pretty stupid question, but on the off chance that
there might be an answer that helps me, I'm asking around.

See... On my laptop, I have to disable ACPI when running NetBSD (or
any BSD) - due to a buggy BIOS, the ethernet and wireless
pseudodevices magically disappear when ACPI is enabled.

That's pretty much okay, because the laptop is a bulky, unweildy model
(an Acer Aspire 3680) that works well as a desktop replacement.
However, there's one problem with it: when ACPI is disabled, hitting
the power button causes the computer to instantly power off, shutting
the system down uncleanly. It would thus be very easy to cause
accidental data loss when running NetBSD.

My question is, is there any way of intercepting the signal from the
power button so that it doesn't cause instant poweroff, without
enabling ACPI? In best case it would be nice for the power button to
invoke a clean shutdown, but I would settle for it doing nothing at
all...

(There's also the little issue that my laptop apparently doesn't have
an APM BIOS, though some sources claim it does; at any rate, enabling
APM doesn't seem to do anything.)